Melt the butter in a thick-bottomed pan. Add the onions, leeks, celery, and garlic, and cook slowly until the juices are released. Stir in the flour until the mixture thickens slightly. Cook several minutes to a blond-brown color. Add the pumpkins, then the coriander, cumin, and chile powders. Cover with a lid and simmer on low heat for 8 to 10 minutes. Remove the lid and add the warm chicken stock. Stir well and bring to a boil. Add the salt and pepper. Simmer 15 minutes and skim the soup. Remove from heat and blend smooth.

To prepare the shrimp, heat the butter in a pan and sauté the garlic. Add the shrimp and sauté briefly until the shrimp change color, about 3 minutes. Distribute the shrimp and garlic evenly into soup bowls, add the pumpkin soup on top, and garnish with the roasted sesame seeds and desiccated coconut. Serve hot.